1. Field of the Invention
This invention relates to a liquid crystal appliance, more paticularly to a display having variable density.
2. Prior Art of the Invention
Liquid crystals have been in use in a variety of displays for electrical appliances, in particular for those requiring compactness, energy efficiency, such as displays of micro computers, word processors, televisions or the like.
In such a display, a system which controls each picture element respectively is efficient. Prior to the invention, twisted nematic liquid crystal was emloyed for an A4 size display which contains 400 elements x 200 elements controlled according to multiplex system. The display assembly, however, has responsibility to high frequency input only of a the order of millisecond or less. Therefore the number of picture elements is limited to about 640 x400 elements or less. In practice, it is impossible to display grey tone which is indispensible for making a color display.